package jiafa;

public class jiafa {
	
	public static void main(String[] args) {
		
		double jiafa = 0;
		
		for(double i = 1; i < 99; i += 2){
			
			double zhong = i / (i + 2);
			
			jiafa += zhong;
		}

		System.out.println(jiafa);
		
	}

}
